Methods for recovering liquids from vegetative materials



March 26, 1963 R. F. CELMER METHODS FOR RECOVERING LIQUIDS FROMLVEGETATIVE MATERIALS Filed April 13, 1959 FIG. I

JUICE OF LOW souos CONTENT CONDITIONED VEGETATIVE PULP CHARACTERIZED BYHIGH FLUID- ITY WITH PREDOMINANT PROPOR- TION OF JUICE-RETAINING PAR-TICLES RUPTURED 0.5"5 BY WEIGHT ALPHA CELLULOSE FIBERS PREDOM- INANTLYI-IOmm. IN LENGTH 5 Sheets-Sheet 1 CONDITIONED PULP WITH ALPHA CELLULOSEFIBERS UNIFORMLY DISTRIBUTED THERETHROUGH IN RANDOM ORIENTATIONCOMPRESSIVE EXTRACTION RESIDUAL PULP LOW IN JUICE AND WITH PULP SOLIDSRE- TAINED BY INTERTANGLED MASS OF ALPHA CELLULOSE FIBERS INVENTOR.

ATTYS.

METHODS FOR RECOVERING LIQUIDS FROM VEGETATIVE MATERIALS Filed April 13,1959 5 Sheets-$heet 2 INITIAL GRAPE PULP FROM STEMMING & CRUSHINGAPPARATUS O.2-O.4% PECTIC SUBSTANCE- DEGRADING ENZYMATIC MATERIAL HEATFOR IO'GO MINUTES AT I Ioo-I25'F. WITH MACERATION I o.s-5% BY WEIGHTALPHA CELLULOSE 2 FIBERS PREDOMINANTLY l-lomm. IN LENGTH HEAT TO RAISEPULP T0 I40- zoo'r. IN 5-30 MINUTES ALTERNATIVE CONTINUOUS SCREWREPLACED BY PULP PRESS CONTINUOUS CENTRIFUGAL EXTRACTOR ALTERNATIVELY 1REPLACED BY RESIDUAL PULP FREE RUN RACK & CLOTH JUICE HYDRAULICRECIPROCATING I PRESS CONTINUOUS SCREW PULP PRESS I I I I I 1 FINALPOMACE PRESS JUICE INVENTOR. RALPH F. CELMR- BY 6/? I M-%' METHODS FORRECOVERING LIQUIDS FROM VEGETATIVE MATERIALS Filed April 13, 1959 5Sheets-Sheet 5 INITIAL GRAPE PULP FROM STEMMING & CRUSHING APPARATUSHEAT TO [IO-175' F.

PULPER PUREE RESIDUAL PULP I-5% BY WEIGHT ALPHA cELLuLosE FIBERS PRE-DOMINANTLY I-IOmm. IN LENGTH CONTINUOUS scREw PULP PRESS RESIDUAL PULP-FREE RUN CONTINUOUS JUICE SCREW PULP PRESS FINAL POMACE 3 PRESS JUICE OIN V EN TOR.

RALPH F. CELMER March 26, 1963 R. F. CELMER 3,083,104

METHODS FOR RECOVERING LIQUIDS FROM VEGETATIVE MATERIALS Filed April 13,1959 5 Sheets-Sheet 4 GRAPE PULP MACERATED AT ROOM TEMPERATURE FIG. 4

CONTINUOUS SCREW PULP PRESS FREE RUN JUICE FEETF ECTIEEIJES TZJC'ETI IDEGRADING ENZY'MATIC MATERIAL I 1 J I"5% BY WEIGHT ALPHA CELLULOSEFIBERS PREDOM- INANTLY l-IOmm. IN LENGTH I RESIDUAL PULP HEAT PULP TOI40-200'F.

IN 5-30 MINUTES CONTINUOUS SCREW PULP PRESS FINAL POMACE March 26, 1963R. F. CELMER 3,083,104

METHODS FOR RECOVERING LIQUIDS FROM VEGETA'I'IVE MATERIALS Filed April13, 1959 FIG. 5

CONTINUOUS SCREW PULP PRESS 5 Sheets-Sheet 5 BULK APPLES O.5'5% BYWEIGHT. ALPHA CELLULOSE FIBERS PREDOM- INANTLY I-lOmm. IN LENGTHDISINTEGRATION AS BY HAMMER MILL LOW SOLIDS CONTENT JUICE FINAL ORRESIDUAL PULP l l I United States Patent- ()fiice PatentedMar. 26, 19633,ilS3,il4 METHODS FOR RECGVERING LIQUEDS FRQM VEGETATEVE MATERIALSRalph F. Ceirner, 28 W. Morris St, Bath, NE. Filed Apr. 13, 1959, Ser.No. 805,915 33 Claims. (Ci. 99-103) This invention relates to theproduction of liquid extractions from vegetative materials andparticularly to an improved process for obtaining, more rapidly andeconomically, improved yields of low solids content liquids from fruitsand vegetables.

Investigators have long attempted to devise a method whereby highlyfluid vegetable or fruit pulps could be pressure extracted withoutclogging of the extractor and without an undue proportion of solidspassing through with the liquid being recovered. Particular attentionhas been given in the past to the possibility of continuous pressureextraction of fruit and vegetable juices with a device such as acontinuous screw press or a centrifugal extractor. But, because of themarked tendency of vegetable pulps to clog such devices and for pulpsolids to pass readily with the juice, little success has been achievedwith continuous methods except in the case of unusual pulps, such asfermented grapes, or when only a relatively small proportion of theavailable liquid is to be recovered.

Because of high labor and material costs, there is a critical need forimprovement in pressure extractions, both with the common hydraulic rackand cloth press and with continuous devices. The need for a successfulcontinuous process is particularly apparent, for example, in the Concordgrape industry.

Because of the extremely slippery, gelatinous nature of the pulpobtained from Concord grapes, it is especially diflicult to continuouslyextract these grapes without clogging of the extractor, and all priorattempts to employ continuous presses on Concord grapes have crnpletelyfailed.

The present invention provides a method for pressure extractingvegetative materials whereby the yields ob, tained with reciprocatingpresses are markedly improved and whereby continuous pressure extractionis, in the case of numerous vegetative materials, made commerciallyfeasible for the first time. Stated broadly, the invention ischaracterized by the provision of a highly fluid pulp, in which theliquid retaining particles are predominantly disrupted, and by theincorporation in such a pulp of relatively small amounts of certainabsorbent alpha cellulose fibers. As will be explained in detail, thefibers must be of a definite type having certain physicalcharacteristics and serve to form an intertangled mass which retains thevegetative solids but allows pressure extraction of the liquid.

When the invention is employed to extract fruit or vegetative juices,the vegetative pulp may first be conditioned, as by action of a pecticenzyme in a preferred embodiment, and the cellulose fibers then added tothe conditioned pulp. Alternatively, the fibers may be added to the pulpalong with the enzyme or even prior to addition of the enzyme. Thus,when processing grapes, it is sometimes preferable to add both theenzyme and the fibers to the pulp received in the crusher sump.Similarly, when processing apples, for example, it is desirable to addthe fibers to the bulk apples before disintegration, as in a hammermill, so that the fibers tend to absorb the juice more readily and aremore uniformly distributed in the pulp.

In many applications, conditioning of the pulp in accordance with theinvention requires best treatment accompanied by gentle maceration.Thus, the pulp maybe agitated by means of a paddle mixer, or circulatedthrough a heat exchanger in such manner that movement of the pulp causesgentle maceration, or circulated by means of a pump having an impellermember designed to macerate the pulp solids. When fluidizing of the pulpis accomplished by means of a pectic enzyme, the action of the enzyme inbreaking down the pulp solids is promoted both by heat and maceration.

While extraction may be accomplished by any suitable pressure extractor,the invention is most advantageous when a continuous screw press or acontinuous centrifugal extractor is employed. A single continuousextractor providing two serially disposed extraction zones, the first ata relatively lower pressure for obtaining free run juice and the secondat a relatively higher pressure for obtaining press juice, may be used.Similarly, two series connected continuous presses may be employed, thefirst extracting free run juice at a relatively low pressure, and thesecond extracting press juice at higher pressure. An-' other suitableprocedure is to treat the conditioned pulp first with a high speedcentrifugal extractor to obtain free run juice, and then to treat theresidual pulp, or pomace, with a continuous screw extractor to obtainthe remaining, or press, juice. Typical suitable extractors of thecontinuous screw type are disclosed in United States Patents 2,664,814,issued January 5, 1954, to C. E. Alborn, and 2,609,744, issued September9, 1952, to C. A. Rietz, while a typical suitable centrifugal extractoris Sharples model PY-l4, described in Bulletin No. 1254, issued 1950, bythe Sharples Corporation, Philadelphia, Pennsylvania.

In accordance with the invention, the desired pulp may be produceddirectly from the bulk fruit or vegetable, or may be obtained byspecially treating an initial pulp. Thus, in the case of vegetativematerials such as apples, pears, carrots, celery, and the like, a highlyfluid pulp in which most of the juice retaining fragments are disruptedmay be obtained by disintegrating the bulk material by means of a hammermill or other suitable comminuting apparatus. In the case of materialssuch as grapes, the material is first crushed to provide an initial pulpof relatively high viscosity and containing a major proportion ofunruptured pulp aggregates, and this initial pulp is then speciallytreated to decrease its viscosity and rupture a predominant proportionof the juice retaining pulp particles.

in a preferred embodiment oi the invention, this conditioning, that is,reducing the viscosity of the initial pulp is accomplished by means of apectic substance-degrading enzyme preparation. Such preparations arereadily available on 'the commercial market in the form, for example, ofan enzyme system including polygalacturonase and pectinesterase(pectase). Such pectic enzyme materails are usually prepared from thegrowth of mold fungi on nutrient media such as wheat or rice bran, wheatmiddlings, and soya bean meal with or without the addition of pectin.Suitable organisms include Aspergillus niger, Aspergillus flavus,Aspergillus oryzae, Aspergillus fumigatws, Aspergillus parasitans,Aspergillus tamarz', Aspergillus wentii, Rhizopus nigrocans, Pennicillamglaztcum, and the like. Extracts are prepared from the culture and areemployed directly as enzyme compositions. Alternatively, the extract maybe treated with a water-miscible, volatile, organic solvent such as alower aliphatic alcohol and the polygalacturonase-pectinesterase systemthen precipitated.

in accordance with the invention, a small amount of the pecticsubstance-degrading enzyme preparation is incorporated in the initialpulp which is then heated at about 160425 F. for about 10-60 minuteswith concurrent agitation of such nature as will provide a gentlemaceration. As the heating and maceration continues, the

pulp becomes markedly more fluid and the freeing of the pulp fragmentsis readily apparent.

In the case of grapes, for example, such enzyme treatment is effectiveto reduce the relative viscosity of the pulp to as low as one third ofits initial value and free floating seeds, skins and pulp fragments areapparent in the more fiuid conditioned pulp.

tandardiza ion of the activity or potency of such enzymatic materials isextremely difiicult. Manufacturers providing such preparations usuallyemploy standardization procedures which are not publicly disclosed and,as a result, competitive products are comparable only With diificulty.As a standard in the present invention, I ascribe unit activity to apectic substance-degrading enzymatic material which, when incorporatedin amounts in the range of (ll-0.4% by weight in Concord grape pulpwhich is then maintained at 110 F. for 1030 minutes with gentlemaceration, will reduce the relative viscosity of such pulp to one halfto one third its initial value. A pectic enzyme preparation having suchunit activity is Pectinol i, a pectic enzyme system referred to as theintermediate product in United States Patent 2,599,531, issued June 16,1952, to Smythe et al'. Such product in eludes polygalacturonase,pectinesterase, and undetermined amounts of other polysaccharidases. Itappears that such enzymatic preparations rupture the juice retainingparticles of the pulp, such effect being apparently due in part to theaction oi} polygalacturonase in splitting the pectic chain and theaction of pectinesterase in hydrolyzing the methyl ester groups of thepectin molecule.

In the treatment of, frutis such as grapes, berries, peaches, cherries,and the like, I have discovered that such conditioning of the pulp bythe enzymatic preparation is enhanced by an additional heating step inwhich the temperature of the pulpis raised, within about 5-30 minutes,to a value of about 140406 F.

While a preferred embodiment of the invention employs enzymatictreatment in conditioning the pulp, and while it is to be understoodthat such treatment is often superior in the case of grapes and otherfruits, I may employ other procedures for conditioning the pulp, as willnow be described.

Initial grape pulp, for example, may be heated at 175- 195 F. for about30-120 minutes with agitation, as in a I paddle mixer or in circulationthrough heat exchange tubes by a pump. Similarly, the pulp may be cookedat higher temperatures under superatmospheric pressure for a shorterperiod of time. Such severe heating may be employed, for example, inpreparing fruit juice for jelly making.

Where the characteristic fresh fruit taste is desired in the product,conditioning may be carried out at room temperature by extensivemaceration. Thus, the pulp may be maeerated for a longer time period, ormay be macerated more vigorously. In the case of cold conditioning ofgrapes, for example, the initial pulp received from the stem-mer andcrusher may be passed through a specially adjusted Fitz mill or the liketo extensively disrupt in a relatively short time all portions of thepulp save the seeds. Materials such as apples may be thoroughlydisintegrated in the cold by means of a. hammer mill or like comminutingapparatus.

As another alternative conditioning procedure, the vegetative materialmay be frozen and then either thawed or disintegrated without priorthawing. In either case, the freezing and thawing action is elfective todisrupt a predominant proportion of the juice retaining particles. Inthe first instance, a preliminary grape pulp, for examaple, is frozenand then thawed to provide a highly fluid conditioned pulp. In thesecond, berries, for example, may be frozen in bulk and the frozenmaterial then disintegrated, as by means of a hammer mill or the like,to provide a slushy pulp.

All such conditioning procedure-s produce a conditioned pulp which isnot suitable for treatment in a continuous pressure extractor. If suchconditioned pulp were passed directly to a continuous screw press, forexample, the press would soon clog and the juice obtained would beunduly high in solids; However, by such conditioning procedures, Iobtain a conditioned pulp of such nature that alpha cellulose fibers maybe uniformly distributed therein to assume a random orientation, thejuice of the pulp being largely available for absorption by the fibers.Then, if suitable fibers are employed, the application of pressure willexpress low solids content juice and the residue will be in the natureof a mass of intertangled fibers in which the pulp solids are entrapped.It will be understood that such conditioning procedures as have beenreferred to disrupt the juice retaining particles of the vegetablematerials in such manner that not only is the juice more readilyavailable but also the pulp solids are so dispersed as to be moreefiectively trapped by the added alpha cellulose fibers.

I have discovered that successful continuous pressure extraction highyields of low yields content juice can be carried out if the addedfibers are soft, absorbent, alpha cellulose fibers substantially freefrom fines and predominantly inthe range of l-lO mm. in length. Whendispersed in the pulp, such fibers soak up a material proportion of thejuice and form an intertangled mass of swollen fibers with small pulpparticles adhered to or adsorbed on the surfaces of the fibers and Withlarger pulp fragments distributed through such mass so as to be trappedor on meshed thereby as the mass is compressed.

While other fibers may have the aforementioned characteristics andtherefore be suitable, the only satisfactory fibers which I have foundto date are the chemically purified alpha cellulose fibers producedeither from the softwoods or from cotton. Very finely divided purifiedwood cellulose, commercially available in average fiber lengths on theorder of 0.3 mm., has been found to be unsuitable for the presentprocess. Similarly, fibers prepared from the hardwoods, predominantlyless than 1 mm. in length, provedrto be not suitable. Further,relatively coarse natural fibrous materials, such as disintegrated Wood,straw, sugar cane bagasse, and the like, are entirely unsuitable in theprocess of this invention. Such materials, employed in their naturalstate, contain hemicelluloses, lignin, and other materials which impartimpurities to the juice. The physical characteristics of suchdisintegrated natural fibrous materials are apparently considerablydifferent from purified alpha cellulose fibers obtained from thesoftwoods and cotton. Thus, I have found that materials such asdisintegrated straw or bagasse not only fail to form the desiredintertangled .mass of soft, absorptive fibers, but they break down inthe vegetative pulp so as to increase the difficulties normallyencountered in attempting to extract untreated fruit or vegetable pulpin a con tinuous pressure extractor. Relatively long purified fibrousmaterials, such as the conventional absorbent cotton" of commerce, havebeen found to be unsuitable in the present process.

A particularly advantageous fibrous material for use in accordance withthe invention is prepared from commereially refined bleached sulfitesoftwood pulp by screening the purified softwood pulp to remove thefines. Commercially available sulfite softwood pulps contain anexcessive proportion of fines, usually on the order of 15% by weight,but can be chemically and physically refined to reduce the fines to anegligible amount. The refined fiber can be provided in the form of softsheets and the sheets may be broken into fragments which, when added tothe vegetative pulp being treated, readily disintegrate to allowdispersion of the fibers. An alpha cellulose fibrous material produeedfrom purified bleached sulfite softwood pulp in this manner ischaracterized by a fiber length predominantly in the range of 1-3 mm.Thus, a typical product, produced by fiufi'ing and screening refinedalpha pulp made from commercial bleached sulfite softwood pulp, had anaverage fiber length of 1.6 mm. with 71.6% of -mately 95%.

*ments of thepresent invention.

- about -30 minutes.

the fibers within the range of '1-3 mm. in length and only 4% passing a100 mesh screen. Alpha cellulose content of this material was'9092%. Ihave made and used loose and fiutfy alpha fibers with less than 1% ofsuch fibers passing through a 100 mesh screen.

Another particularly advantageous fibrous material is the commerciallyavailable filtermass manufactured from long fiber cotton. The purifiedalpha cellulose fibers of such filtermass are predominantly longer than1 mm. and less than mm. The alpha cellulose content is approxi- Flufiedmaterial low in fines can also be made from cotton cellulose.

It is to be understood that the predominant fiber length of the alphacellulose fibers is of extreme importance to successof the continuouspressure extraction. .If the libers be too short, as when they arepredominantly shorter than 1 mm., they will not only tend to passthrough into the juice but will also fail to form the intertangled fibermass necessary to trap the pulp solidsh If the fibers be too long, theywill tend to ball up in the continuous-ex- -tractor, again preventingformation of the required intertangled fiber-mass.

I have found that fibers having the characteristics referred to areeffective in thepresent invention when incorporated in the vegetablepulp in proportions in the range of 0.5-5 by weight of the pulp.

FIGS. 15 illustrate flow sheets for various embodi- As seen in FIG. 1,to a vegetative pulp specially conditioned by any of the aforementionedconditioning procedures is added-0;'55% by weight of the alpha cellulosefibers hereinbefore specified to provide apulp in which the fibers areuniformly distributed in random orientation. The pulp is then fedthrough a continuous screw pulp press or, alternatively, through acontinuous centrifugal extractor or a conventional reciprocating press.The pulp may be flowed to such apparatus either by pumping or bygravity. The continuous pressure extractor provides, on the one hand,

.a low solids content juice and, on the other hand, a rela- .aconventional stemmer and crusher is combined with .2.4% by weight of apectic substance-degrading enzymatic material such as the aforementionedPectinol M, The pulp is then heated for 10-60 minutes at 100-125 F., asin a glass-lined heating and mixing tank, or a conveying heat exchanger,or other suitable means wherein both'heating and maceration can beaccomplished concurrently. O.55% by Weight alpha cellulose fibers havingthe hereinbefore specified characteristics is added at the end of suchoperation, or before heating is started, or while heating and macerationis carried on, or in the following step. The pulp is then raised to140-200 F. in The pulp so conditioned is then flowed through acontinuousscrew pressoperated at higher speed, lower pressure to recoverfree run juice. The residual pulp is passed continuously through asecond continuous screw pulp press operated at lower speed, higherpressure to recover press juice. Alternatively,-the

first continuous screw press may be replaced by a continuous centrifugalextractor.

As indicated in FIG. 3, initial grape pulp as received from aconventional stemming and crushing apparatus may be heated to 1'10175 F.and treated with a pulper to separate a puree, ordinarily about 75%ofthe pulp, from a residual pulp. To the puree is added 15% by Weight ofthe aforementioned alpha cellulose fibers, the

puree then being flowed through .a continuousscrew press to separatefree run juice from a residual pulp containing a relatively highproportion by weight of alpha cellulose fibers. Such residual pulp isthen combined with the residual pulp from the pulper and the combinedresidual pulp passed through a continuous screw pulp press to recoverthe press juice.

As seen in FIG. 4, grape pulp which has beenmacenated at roomtemperature is combined with l-5% by weight of the aforementioned alphacellulose fibers and passed at room temperature through a continuousscrew pulp press to separate free run juice from residual pulp. Thelatter is then heated to 140-200 F. within 5-30minutes and the'heatedpulp passed through a second continuous screw press for hot pressing ofthe press juice. The hot press juice may then be combined in desiredproportion with the free run juice, the latter having a characteristicfresh fruit flavor. Alternatively, .2-.'4% of apecticsubstance-degrading enzymatic material may be added prior to the firstpressing step to better condition the pulp and increase the yield offree run juice.

As seen in FIG. 5, the alpha cellulose fibers maybe added to the bulkmaterial before disintegration when the invention is employed to obtainjuice from vegetative materials of the class consisting of apples,pears, quinces, peeled pineapples, peel-free pineapple fragments,carrots, beets, rhubarb and celery. The bulk materialincluding thefibers is then disintegrated in a hammer'mill or the like and theresulting pulp passed through a continuous screw extractor torecover lowsolids content juice. In some cases, depending upon the nature of thematerial being treated, the pulp from this operation may be passedthrough a second .continuous screwpulp press to recover press juice.

The following examples are illustrative:

Example -1 One hundredgallons (890 pounds) of stemmed-and crushedConcord grapes were received at 70 F. in a glasslined mixing tank. Threepounds 0.34% by weight). of Pectinol M (a pectic enzyme preparations,comprising polygalacturonase and pectinesterase, and being in'the natureof the intermediate product referred to inUnited States Patent2,599,531, issued June 10, 1952, to Smythe et .al.) was added to thepulp and thepulp agitated for 10 minutes to insure even distribution ofthe enzyme.

The pulp was then circulated through a vacuum steam preheater at F. for30 minutes. The mixing tank, pump and preheater Were connected inaseriesclosed ClICUllI so'that the pulp was continuously macerated byaction of the mixer and pump. A marked increase in fluidity of 'the pulpmass was noted, and it was observed that seeds, skins and .pulpfragments floated freely in the pulp. The relative viscosity of the.pulp was reduced by this treatment to less than one half its initialvalue.

Five pounds (0.5%) of soft, fiufied, purified, bleached, sulfite Woodpulp which had been substantially freed of fines was then added to thepulp and thoroughly. dispersed This material had an average fiber lengthof 1-3 mm. in length and only 4% passing a 100 mesh 'A-lpha cellulosecontent ofthe fibrous material was 90-92%.

The conditioned pulp, with the fibrous material dis .persed therein, wasthen circulated through the heat exchanger for 15 minutes with the heatexchanger temperature at F. Terminal temperature of the pulp was 138 F.

With the mixer continually agitating the pulp at 138 F., the pulp wasthen pumped through a conventional horizontal, centrifugal extractor(Model PY-14: Super- D-Canter described in Bulletin No. 1254,issued in1950, the Sharples Corporation, Philadelphia, Pa.) at the rate of 15gallons per minute. The extracted free run juice broke its foam quickly,had a good deep color, and centrifugingtests showed asolids content ofonly-0.3% by volume. Theresidual pulp or pomace'discharged from theextractor as loose, moist pellets of skins, seeds and cell debrisenmeshed in the tangled cellulose fibers and havcontinuous extraction oflow solids press juice.

- weighed 85 pounds or 11.4% by weight of the original pulp. This pressjuice showed a solids content of 3% by volume. The final pomacedelivered by the continuous press amounted to 8.3% by weight of theoriginal pulp and was a crumbly, semi-dry mass from which the seeds wereeasily separated. Such pomace can be dried at a lower temperature andfaster rate than can the po-mace from conventional hydraulic pressextractions, so facilitatmg by-product recovery Total juice recovery was91.7%

by weight of the original pulp.

Example 2 The procedure of Example 1 was followed, except that 0.56% ofSolka-Floc BW20, a disintegrated purified wood cellulose having anaverage fiber length of 0.3 mrn., was employed in place of the bleachedsulfite pulp of Example 1. A yield of 70% free run juice was obtainedfrom the centrifugal extractor, but this juice had a suspended solidscontent of 7% by volume and included an excessive amount of skin flakes.The residual pulp from the centrifugal extractor was a sludge having amoisture content of 64.3% unsuitable for satisfactory extraction torecover the residual, or press, juice of low solids content.

Example 3 Two hundred sixty-five gallons (2360 pounds) of stemmed andcrushed Concord grapes was received in a glassdined mixer at 65 F. andheated to 100 F. Five pounds (0.25% by weight) of Pectinol M was thenadded and the pulp mixed for 30 minutes at a continuing temperature of100 F. A definite increase in fluidity of the pulp was noted at thisstage. With agitation continuing, the temperature of the. pulp was thenraised progressively over a period of 30 minutes to a final value of 160F. A very highly fluid pulp resulted.

Twenty three pounds, ten ounces (1.0% by weight) of the cellulose fiberemployed in Example 1 was then added and the pulp was then mixed for 10minutes to The pulp was then pumped to the hopper of the com tinuousvertical screw-press and thence delivered to the press at a press intakerate of approximately 2.5 tons per hour. Starting counter pressure onthe press was 120 pounds until a cake formed, the counter pressure thenbeing adjusted to 65 pounds. Free run juice was obtained at the rate of43 pounds per minute. Total free run juice was 1794 pounds (200 gallons)or 76% by weight of the original pulp. Suspended solids content of thfree juice was 3.2% by volume. The residual pulp was placed in thehopper of a vertical continuous screw press. The press was operated witha counter pressure of 100 pounds and at an intake -rate of approximatelyZtons per hour. The residual, or

press, juice obtained was 378 pounds (42.5 gallons) or 16% by Weight ofthe original pulp. Suspended solids content of the press juice was 3.9%by volume.

Note: Conventional use of this press, without employing the process ofthis invention, produces a free run juice with a suspended solidscontent in excess of 10% by volume and a residual pulp which is notsuitable for The screens in this particular press have .04" openings.For the invention, screens having openings .02.03" in diameter can beemployed.

'8 Example 4 The free run and press juices obtained in Example 3 werecombined with other Concord grape juice higher in solids content toprovide a combined juice with a suspended solids content of 5% byvolume. To 'a batch of 320 gallons (2848 pounds) of the combined juice,heated at 170 F., was added 12.5 pounds (0.39% by weight) of thecellulose fiber employed in Example 1, the juice then being agitated for15 minutes to thoroughly disperse the fibers.

The juice was then passed through the centrifugal extractor employed inExample 1 at the rate of 150 pounds per minute. The clarified juicetotaled 2822.5 pounds, a 98.7% recovery, and showed a suspended solidscontent of 0.6%. Thus, 88% of the solids was removed.

Example 5 To thirty'pounds of stemmed and crushed Concord grapes at F.was added 0.4% by weight of Pectinol l\ The pulp was then mixed by handwith a blunt paddle intermittently for 40 minutes. At the end of thisperiod, 1% by weight of the cellulose fiber employed in Example 1 wasadded. The pulp was then mixed for an additional 20 minutes. Thetemperature was maintained at approximately 80 F. throughout theentiremixing period. At the end of this time, the pulp was observed to bematerially more fluid than the original pulp.

The pulp was then extracted with a horizontal continuous screw pressequipped with a .02 screen to obtain free run juice totalling 17.5pounds (58.3% by weight of the original pulp) and having a suspendedsolids content of 0.7% by volume. The residual pulp, amounting to 41.7%of the original pulp, was in suitable condition for satisfactorycontinuous extraction of the press juice.

Example 6 To thirty pounds of stemmed and crushed Concord grapes at 80F. was added 0.4% by weight of Pectinol M. The pulp was then heated atF. for 20 minutes with continual maceration by means of a blunt handpaddle. At the end of this period, 1% by weight of the cellulose fiberemployed in Example 1 was added, and heating then continued, accompaniedby maceration, for an additional 10 minutes. The resulting pulp wasconsiderably more fluid than that obtained in Example 5.

The pulp was then extracted with a horizontal continuous screw pressequipped with a .0 screen to obtain free run juice totalling 21 pounds(70% by weight of the original pulp) and having a suspended solidscontent of 0.4% by volume. The residual pulp, amounting to 30% by weightof the original pulp, was in suitable condition for satisfactorycontinuous extraction of the press juice.

Example 7 Two 10-pound lots of stemmed and crushed Concord grapes wereseparately cooked at 15 pounds steam pressure (226.9 F.) for 5 minutesand combined to provide an extremely fluid pulp. To this pulp was thenadded 1% by weight of the cellulose fibers employed in Example 1, thepulp then being mixed for 20 minutes without additional heating. Thetemperature of the pulp at the end of the mixing operationwas 190 F.

The pulp was then extracted with a horizontal continuous screw pressequipped with a .02" screen to obtain free run juice totalling 16.4pounds (82% by weight of the original pulp) and having a suspendedsolids content of 0.5% by volume. The residual pulp, amounting to 18% ofthe original pulp, was in suitable condition for continuous extractionof press juice.

Example 8" A Concord grape pulp received from conventional crushing andstemming apparatus is heated to F. and 0.4% by weight Pectinol M addedthereto. The

pulp is then maintained at 110 F. for 30 minutes while continuallyagitating thepulp to macerate the same.

The resulting highly fluid pulp is sieved by means of a pulping machineto separate a thin puree, constituting approximately 75% by weight ofthe original pulp, from a residue consisting of a wet mixture of seedsand adhering pulp and skin fragments.

To the thin puree is then added 1% by weight of the alpha cellulosefibers employed in Example 1, the puree then being mixed for minutes todisperse the fibers uniformly therethrough. The puree is then passedthrough the centrifugal extractor of Example 1 to separate a high yieldof low solids content juice from a residual pulp containing thecellulose fibers. Such residual pulp is then combined with the residuefrom the pulping machine and the combined product extracted in acontinuous screw press to recover the press juice.

Example 9 An initial Concord grape pulp as received from. theconventional stemmer and crusher is heated to about 175 F. withaccompanying agitation and then sieved through a pulping machine toseparate a thin puree from a residue consisting of a Wet mixture ofseeds and adhering pulp and skin fragments. 4% by Weight of the alphacellulose fibers of Example 1 are then added to the puree and disperseduniformly by agitating the puree for 10 minutes.

The puree is then passed through a continuous screw press of the typedisclosed in Patent 2,664,814 to separate a high yield of low solidscontent juice from a residual pulp containing the cellulose fibers. Thisresidual pulp is then combined with the residue from the pulping machineand extracted in a continuous screw .press of the type just referred toin order to recover the press juice.

Example 10 Three thousand pounds (337 gallons) mushy, overripe Concordgrapes were stemmed and crushed, the resulting pulp then being heated to110 F. Twelve pounds (0.4% by weight) of Pectinol M was then added tothe pulp and mixing was continued for 30 minutes while maintaining the110,F. temperature.

Over a period of minutes, the pulp was then heated to 138 F. Twenty-fivepounds (0.83%) of the cellulose fibers of Example 1 were then added andmixing continued for 10 minutes.

2817 pounds of the resulting pulp was then pumped through thecentrifugal extractor employed in Example 1 at a rate of 150 pounds perminute. The free run juice so obtained totalled 2423 pounds, or 86% byweight of the pulp extracted, and was free from skin flakes with asolids content of 0.8% by volume.

The residual pulp, amounting to 394 pounds, was then extracted at a rateof 2 tons per hour with a vertical continuous screw press of the typedisclosed in Patent 2,664,814 with the counter pressure set at 80pounds. This extraction step recovered 197 pounds of press juice havinga suspended solids content of 3.0% by volume. Total juice extracted fromthe over-ripe grapes was thus 93% by weight.

Example 11 74 ounces of washed McIntosh apples were combined with 1% byweight of the alpha cellulose fibers ofExample l and then disintegratedto a fluid pulp. The pulp was then passed through a horizontalcontinuous screw extractor with .02" screen, giving a free run juice of35 ounces, or 47.3% by weight, having a suspended solids content of 2%by Volume.

The residual pulp containing the cellulose fibers was then passedthrough the same extractor, using a higher counter pressure, to obtain19 ounces of press juice containing 3% "by volume suspended solids.Total juice recovered was 72% by weight of the bulk apples treated.

p in Example 12 Two pounds of washed dried prunes were combined with 4pounds of water and pressure cooked at 15 pounds stream pressure for 10minutes. The pressure cooker was then drained, giving an extractamounting to 3.5 pounds (.38 gallon). The 2.5 pounds of remaining pulpand seeds was put through a food mill to separate 2 pounds of puree.

To the puree was then added 2% by weight of the alpha cellulose fibers.The puree was then passed through a horizontal continuous screw presswith .02"

screen to recover 1.8 pounds of juice having a suspended solids contentof -.35% by volume.

Example 13 Two pounds, 13 ounces of pulpy orange juice, obtained byreaming orange'halves on a conventional household reamer and containing.a highrag content and 10% by weight finer solids,-was combined with .5by weight of the alpha cellulose fibers of Example land agitated todisperse the fibers. The material was then passed through a horizontalcontinuous screw press, yielding a juice containing less than 1% byvolume of suspended solids. The residualpulp recovered from theextraction zone was characterized by the fact that the alpha cellulosefibers were colored a deep yellow, having picked up a substantialproportion of the pigment otthe juice.

Example 14 Crushed and stemmed over-ripe Concord grapes amounting to2045 grams were combined with .4% by weight Pectinol M and heated at F.forabout 30 minutes with concurrent maceration. This conditioned pulpwas then heated to F.

To-the resulting highly fluid grape pulp was then added 1% by weight ofthat filter-mass mentioned hereinbefore, a soft sheet filtermassmanufactured from cotton linters and consisting of purified alphacellulose fibers substantially free from finesand predominantly somewhatless than 10 mm. in length. The filtermass sheet was broken intofragmentsbefore addition to the plupand these fragments readilydisintegrated toallow uniform distribution of the fibers in a fewminutes mixing time.

Thepulp was then passed through a continuous horizontal screwpresshaving a .02" screen, yielding a free run juice amounting to 72.2%by weight of the original pulp and having a suspended solids content of0.8% by volume.

The residue from this pressing operation was then passed again throughthe same press, operating under higher pressure,.yielding a press. juiceamounting to 17.8% by weight of the original pulp and having a suspendedsolids content of 1.2% by volume.

Example 15 A few quarts of home canned peaches were drained and then putthrough a food mill to simulate the action of a commercial pulpingapparatus. To the resulting pulp was added 1% by weight of the alphacellulose fibers of Example 1. The pulp was then mixed for 15 minutes todisperse the fibers and allow absorption of the juice.

The pulp was then put through a horizontal continuous screw extractorwith a .02" screen, obtaining 60% by Weight free run juice having asuspended solids content of 1.2% by volume. The residue was an easilycompressible semi-solid mass suitable for further extraction in acontinuous screw press.

Example 16 Several half grapefruit peels were cut into strips andreduced to relatively finely chopped form by means of a No. 72 Universalfood chopper equipped witha 16-tooth blade. The total of 343.5 gramschopped peel was combined with 1030.5 grams water, brought to a boil,drained, and the solid residue lightly pressed to provide a crumblymass. Such mass was combined with an additional 1030.5" grams water andthis was treated with hydrochloric wasthen heated at 200 F. for 25minutes, yielding 1417.5 grams of a thick, gelatinous puree containingtranslucent particles.

To this puree was added 1.5% by weight of the alpha cellulose fibers ofExample 1. i The puree was then passed through a continuous horizontalscrew press, producing 60% by weight pectin extract substantially freeof solids. The residue from this pressure extraction step, containing88% by weight moisture, was passed again through the press under higherpressure. Yielding an additional 16% by weight of pectin extractsubstantially free from solids. Moisture content of the final residuewas 62% by weight.

7 Example 17 To simulate commercial extraction of starch from potatoes,455 grams of potato pulp was obtained'by rasping cleaned Katadinpotatoes. A slurry was prepared by combining this pulp with 4550 gramswater.

starch to settle and decanting the slurry.

To the remaining slurry, amounting to. approximately 4490 grams, wasadded 1% by weight (of the original potato pulp) of the alpha cellulosefibers of Example 1, the fibers being uniformly distributed by mixing.The slurry was then passed through a horizontal continuous -screw presswith a .02" screen for initial dewatering.

The'residual pulp amounted to 179 grams and dried readily to 32 gramswithout any material tendency to form a sticky mass which would bedifiicult to remove from the drier. The water discharged from the presscontained materially less than 1% by volume suspended solids.

As has been pointed out, the process of this invention employs 0.5'5% byWeight of alpha cellulose fibers low in fiines and predominantly in therange of 1-10 mm. in length. The particular quantity of fibers, withinthe weight range specified, depends upon both the-material being treatedand the type of pressure extraction equipment employed to carry out theprocess. Thus, for example, where certain types of centrifugalextractors are to be employed, the proportion of alpha cellulose fibersis advantageously kept within the range of 05-15% by 1 weight to assureready flow of the material through the extractor. On the other hand,Where a particularly fluid pulp is to be treated in a continuous screwpress or in a reciprocating hydraulic press, the alpha cellulose fibersmay advantageously be kept within the higher portion of the range. A

The effectiveness of the alpha cellulose fibers employed, and also ofthe preferred pulp conditioning procedures of the invention, isillustrated by the following table showing extractions on. a hydraulicrack and cloth press. Here, pulp A is a Concord grape pulp conditionedsolely by heating and macerating at 145 F., while pulp B is a Concordgrape pulp conditioned by adding 0.3% by weight Pectinol M pecticsubstance-degrading enzymatic material, macerating at 110 F. and heatingthen to 145 F.

Suspended Yield Solids (Gals/ton (Percent by of pulp) volume) 1. Pulp Awith no additive 1. 3 188 2. Pulp A with 0.5% diatomaceous earth filteraid 1.5 189 3. Pulp A with 0.5% disintegrated purified wood fiberspredominantly 0.3 mm. in length 0.9 189 Pulp A with 0.5% alpha cellulosefiber of Example 1 0.3 195 Pulp B with no additive 2.6 195 Pulp B with0.5% diatomaecous earth filter aid 2. 2 195 Pulp B with 0.5%disintegrated purified wood fibers predominantly 0.3 mm. in len th 1. 8192 8. Pulp B with 0.5% alpha cellulose fibers of Example 1 0. 5 200 Inexcess of 90% of the starch was separated out by allowing the Except inthe case of procedures 4 and 8 of the foregoing ta-ble, continuouspressure extraction, as in a centrifugal extractor or a continuous screwpress, could not be carried out acceptably. As has been pointed out,effectiveness of the present process is dependent upon the ability ofthe particular alpha cellulose fibers to form a swollen intertangledmass which may be highly compressed for maximum exrtaction of the juicewithout an excessive proportion of the pulp solids, which arecharacterized by a high degree of slippage, escaping from the mass toenter the extracted juice or clog the extraction apparatus, and withoutany material passing with the uice. 7

It will be apparent that the foregoing portion of this specificationprovides a basis for a process for conditioning grape materialpreparatory to the extraction of juice therefrom and which processcomprises adding to a mass of grape material a pectin hydrolyzing agent,and finely divided wood pulp fiber, the latter being characterized by asurface rough through the presence of hair-like processes enabling it tohold contacting solids particles freed in the mass as the result ofdisintegration of the fruit tissue, dispersing the additives throughoutthe mass by mixing, whereby the wood pulp fiber forms a threedimensional web-like network throughout the mass positioned tointercept, and inhibit the independent migration of, said particles, andmaintaining the mixture at a temperature Within the reaction range ofthe hydrolyzing agent tor a sufiicient time to obtain a substantialhydrolyzing efiect, then progressively reducing the volume of the mass,whereby the juice is extracted independently of the solids particles,the latter being retained in their relatively dispersed positions insaid mass.

'to 0.2% by weight of a pectin hydrolyzing enzyme, and

0.2% to 0.5% of finely divided Wood pulp fiber having certaincharacteristics. These percentages overlap the amounts specified earlierin this specification. By this method there is also provided treatmentof the mass within the temperature range of from substantially 100 F.

'to 130 F. for a duration of substantially from thirty minutes to onehour.

This is a continuation-in-part of my application for patent Serial No.456,247, filed September 15, 1954, Methods for Recovering Liquids fromVegetative Materials, now

abandoned.

' I claim:

1. A method for obtaining a high separation of liquids from solids in ahighly fluid vegetative pulp a predominant .proportion of the liquidretaining particles of which are ruptured, comprising uniformlydistributing in such pulp 055% by weight of alpha cellulose fiberssubstantially free from fines and predominantly in the range of l-lO mm.in length, and then subjecting the pulp to compressive extraction toseparate the liquid from a residual pulp comprising pulp solids retainedby an intertangled mass 2. A method for obtaining high yields of lowsolids content juice from vegetative materials comprising crushing suchmaterial to provide an initial pulp, disrupting a predominant proportionof the juice retaining particles of content juice from fruits comprisingpreparing an initial pulp of the fruit, incorporating in said initialpulp a pectic substance-degrading enzyme preparation in amount not lessthan 0.2 nor more than 0.4% by Weight of the initial pulp, heating saidinitial pulp with its added enzyme preparation at about 100-125 F. forabout 10-60 minutes while macerating the pulp, whereby a conditionedpulp is produced characterized by high fluidity and a predominantproportion of ruptured juice retaining particles, uniformly distributingin said conditioned pulp 0.5- by weight of alpha cellulose fiberssubstantially free from fines and predominantly in the range of 1-10 mm.in length, and then subjecting said conditioned pulp to compressiveextraction to recover the juice therefrom.

4. A method for obtaining high yields of low solids content juice fromfruits comprising preparing an initial pulp of the fruit, incorporatingin said initial pulp a pectic substance-degrading enzyme preparation inamount not less than 0.2 nor more than 0.4% by weight of the initialpulp, heating said initial pulp with its added enzyme preparation atabout 100-125 F. for about -60 minutes while macerating the pulp, thensupplying additional heat to said pulp to raise the temperature thereofto a terminal value of 140-200 F. in atime period of 5-30 minutes,uniformly distributing in said pulp 0.5-5 by Weight of alpha cellulosefibers substantially free from fines and predominantly in the range of1-10 mm. in length, and then subjecting the pulp to compressiveextraction to recover the juice therefrom.

5. A method for obtaining high yields of low solids content juice fromConcord grapes comprising crushing and stemming the grapes to provide aninitial pulp, incorporating in said initial pulp a pecticsubstance-degrading enzyme preparation in amount not less than 0.2 normore than 0.4% by weight of the initial pulp, heating said initial pulpwith its added enzyme preparation at about 100- 125 F. for about 10-60minutes While macerating the pulp, then supplying additional heat to thepulp to raise the temperature thereof to a terminal value of about 140-175 F. in a time period of 5-30 minutes, uniformly distributing 0.5 %-5%by weight of alpha cellulose fibers substantially free from fines andpredominantly in the range of l-10 mm. in length, and then continuouslypressure extracting said pulp to recover the juice therefrom.

6. A method for obtaining high yields of low solids content juice fromgrapes comprising crushing and stemming the grapes to provide an initialpulp, sieving said initial pulp to separate the same into a puree and aresidual pulp, uniformly distributing in said puree 1-5% by weight ofalpha cellulose fibers substantially free from fines and predominantlyin the range of 1-10 m-m. in length, passing said puree continuouslythrough a pressure extracting zone to recover free run juice and providea second quantity of residual pulp containing said fibers, combiningsaid second quantity of residual pulp with the residual pulp from saidsieving operation, and passing the combined residual pulp through acontinuous pressure extraction zone to recover press juice.

7. A method for obtaining high yields of low solids content juice from avegetative material comprising crushing such material to provide aninitial pulp, disrupting a predominant proportion of the juice retainingparticles of said initial pulp to provide a highly fluid conditionedpulp, uniformly distributing in said conditioned pulp a small proportionof alpha cellulose fibers substantially free from fines andpredominantly in the range of 1-10 mm. in length, said small proportionbeing in the range of 05-15% by weight but less than that amount whichwill so thicken the pulp that the same will not flow through acentrifugal extractor, continuously flowing said pulp through acentrifugal extraction zone, recovering from said centrifugal extractionzone free run juice and a residual pulp consisting of pulp solidsretained by an intertangled mass of said fibers, and pressure extractingsaid residual pulp to recover press juice therefrom.

8. A method for treating grapes comprising crushing the grapessubstantially at room temperature to obtain an initial pulp, disruptinga predominant proportion of the juice retaining fragments of said pulpwhile the same is substantially at room temperature to produce aconditioned pulp characterized by markedly increased fluidity, uniformlydistributing in said conditioned Pulp 1-5% by weight ofalpha cellulosefibers substantially free from fines and predominantly in the range of1-10 mm. in length, then passing said conditioned pulp substantially atroom temperature continuously through a pressure extraction zone toobtain a cold pressed free run juice having a characteristic fresh grapeflavor, recovering from said zone a residual pulp consisting of grapepulp solids retained by an intertangled mass of said fibers, andcontinuously pressure extracting said residual pulp.

9'. A method for treating grapes comprising crushing the grapessubstantially at room temperature to obtain an initial pulp, disruptinga predominant proportion of the juice retaining fragments of said pulpwhile the same is substantially at room temperature to produce aconditioned pulp characterized by markedly increased fluidity, uniformlydistributing in said conditioned pulp 15% by weight of alpha cellulosefibers substantially free from fines and predominantly in the range ofl-10 mm. in length, then passing said conditioned pulp substantially atroom temperature continuously through a pressure extraction zone toobtain a cold pressed free run juice having a characterized fresh grapeflavor, recovering from said zone a residual pulp consisting of grapepulp solids retained by an intertangled mass of said fibers, heatingsuch residual pulp to from about 140 F. to about 200 F., andcontinuously pressure extracting said heated residual pulp.

10. A method for treating grapes comprising crushing the grapessubstantially at room temperature to obtain an initial pulp,incorporating in said initial pulp a pectic substance-degrading enzymepreparation in amount not less than 0.2 nor more than 0.4% by weight ofthe initial pulp, macerating said pulp with its added enzyme preparationwhile substantially at room temperature for about 10-60 minutes,uniformly distributing in said pulp 1-5% by Weight of alpha cellulosefibers substantially free from fines and predominantly in the range ofl-10 mm. in length, then passing said pulp and added substancesubstantially at room temperature continuously through a pressureextracting zone to obtain a cold press-free run H juice having acharacteristic fresh grape flavor, recovering from said zone a residualpulp consisting of grape pulp solids retained by an intertangled mass ofsaid fibers,

and continuously pressure extracting said residual pulp.

11. A method for treating grapes comprising crushing the grapessubstantially at room temperature to obtain an initial pulp,incorporating in said initial pulp a pectic substance-degrading enzymepreparation in amount not less than 0.2 nor more than 0.4% by weight ofthe initial pulp, macerating said pulp with its added enzyme preparationWhile substantially at room temperature for about 10-60 minutes,uniformly distributing in said pulp 1-5% by weight of alpha cellulosefibers substantially free from fines and predominantly in the range of1-10 mm. in length, then passing said pulp and added substancesubstantially at room temperature continuously through a pressureextracting zone to obtain a cold press-free run juice having acharacteristic fresh grape flavor, recovering from said zone a residualpulp consisting of grape pulp solids retained by an intertangled mass ofsaid fibers, heating such residual pulp to from about 140 F. to about200 F., and continuously pressure extracting said heated residual pulp.

12. A method for obtaining high yields of low solids content juices fromvegetative materials of the class consisting of carrots, beets, celery,rhubarb, apples, pears,

quinces, peeled pineapples and peel-free pineapple fragrial 0.5- byweight of alpha cellulose fibers substan- 'tially free from fines andpredominantly in the range of lmm. in length, then mechanicallydisintegrating said vegetative material to produce a fiuid pulp in whichsaid fibers are uniformly dispersed, and passing said pulp continuouslythrough a pressure extraction zone to recover the juice therefrom.

13. A method for obtaining high yields of low solids content juice fromdried prunes comprising adding water to the prunes, cooking the prunes,draining the cooked prunes to recover the extract, forming a seed-freepuree from the drained cooked prunes, uniformly distributing in saidpuree 1-5% by weight of alpha cellulose fibers substantially free fromfines and predominantly in the range V a pressure extraction zone torecover the juice therefrom,

and recovering from said extraction zone a residual pulp consisting ofpulp solids retained by an intertangled mass of said fibers, said fiberscarrying a substantial proportion of the pigment of said material.

15. A method for obtaining high yields of low solids content juice frompulpy mass of citrus fruit material, comprising uniformly distributingin said pulpy mass alpha cellulose fibers, substantially free from finesand predominantly in the range of 1-10 mm. in length, and in amountseffective to condition the pulp by absorption of the liquid and to forma swollen intertangled mass, and then progressively reducing the volumeof the mass whereby the juice is extracted independently of solidparticles, the latter being retained in their relatively dispersedpositions in said mass.

16. A method for treating aqueous potato waste from the extraction ofpotato starch comprising uniformly distributing in such waste OJ-5% byWeight of alpha cellulose fibers substantially free from fines andpredominantly in the range of 1-10 mm. in length and then subjecting thewaste to continuous pressure extraction to separate a low solids contentaqueous liquid from a residue consisting of potato solids retained by anintertangled mass of 7 said fibers.

17. A method for recovering high yields of a low solids content pectinextract from citrus peel comprising comminuting the peel, combining thepeel with water and heating the resulting suspension to form agelatinous puree, uniformly distributing in such puree 0.55% by weightof alpha cellulose fibers substantially free from fines andpredominantly in the range of 1-10 mm. in length, and then passing thepuree through a continuous extraction zone to separate the pectinextract from a residue consisting of citrus peel solids retained by anintertangled mass of said fibers.

18. Process for conditioning grape material preparatory to theextraction of juice therefrom, comprising adding to a mass of grapematerial a pectin hydrolizing agent,

and finely divided wood pulp fiber, the latter being characterized by asurface rough through the presence of hair-like processes enabling it tohold contacting solids particles freed in the mass as the result ofdisintegration of the fruit tissue, dispersing the additives throughoutthe mass by mixing, whereby the Wood pulp fiber forms a threedimensional web-like network throughout the mass positioned tointercept, and inhibit the independent migration of, said particles, andmaintaining the mixture at a temperature within the reaction range ofthehydrolizing agent for a sutficient' time to obtain a substantialhydrolizing effect, then progressively reducing the volume of the masswhereby the juice is extracted independently of the solids particles,the latter being retained in their relatively dispersed positions insaid mass.

19. Process for conditioning grape material preparatory to theextraction of juice therefrom, comprising adding to a mass of grapematerial from 0.1% to 0.2% by weight, of a pectin hydrolizing enzyme,and 0.2% to 0.5% of finely divided wood pulp fiber, the latter beingcharacterized by a surface rough through the presence of hair-likeprocesses enabling it to hold contacting solids particles freed in themass as the result of disintegration of the fruit tissue, dispersing theadditives throughout the mass by mixing, whereby the wood pulp fiberforms a three dimensional web-like network throughout the masspositioned to intercept, and inhibit the independent migration of, saidparticles, and maintaining the mixture at a temperature within thereaction range of the hydrolizing agent for a sufiicient time to obtaina substantial hydrolizing effect, then progressively reducing the volumeof the mass whereby the juice is extracted independently of the solidsparticles, the latter being retained in their relatively dispersedpositions in said mass.

20. The method of extracting juice from fruit material containing nativepectin, comprising conditioning the material preparatory to the juiceextraction by adding thereto from 0.1% to 0.2% by weight of a pectinhydrolizing enzyme, and from 0.2% to 0.5% by weight of finely dividedfibrous material having the rough surface characteristics of wood pulpfiber which enable it to hold contacting solids particles freed in themass as the result of disintegration of the fruit tissue, agitating themixture of said material and additives to secure uniform dispersion ofthe additives throughout the mass whereby the particles holding materialforms a three dimensional web-like network throughout the masspositioned to intercept, and inhibit the independent migration of, saidparticles, holding the mass within a temperature range of fromsubstantially F. to F. for a duration of substantially from thirtyminutes to one hour, separating the optimum amount of substantiallysolids-free juice from the thus conditioned material, leaving a mass ofsolids with residual juice, and separating the extractable residualjuice from said mass, then progressively reducing the volume of the masswhereby the juice is extracted independently of the solids particles,the latter being retained in their relatively dispersed positions insaid mass.

21. In a method for obtaining high yields of low solids content juicefrom Concord grapes wherein there has been prepared an initial pulp ofthe grapes and the relative viscosity of said pulp has been decreased tofrom one half to one third of its original value by incorporating insaid initial pulp a pectic substance-degrading enzyme preparation inamount not less than 0.2 nor more than 0.4 percent by weight of theinitial pulp and said pulp with added enzyme preparation has been heatedat about 100-125 F. for about 10-60 minutes while macerating the pulp,the steps of distributing into said pulp of decreased viscosity 0.5-5percent by weight of alpha cellulose fibers substantially free fromfines and predominantly in the range of 1-10 mm. in length, and thenpassing said pulp continuously through a pressure extraction zone torecover the juice therefrom.

22. A process for conditioning grape material preparatory to theextraction of juice therefrom comprising crushing and stemming grapes toprovide an essential pulp, incorporating in said initial pulp a pecticsubstance degrading enzyme preparation in amount not less than 0.2 normore than 0.4% by weight of the initial pulp, heating said essentialpulp with its added enzyme preparation while macerating the pulp, addingto the macerated pulp cellulose fibers derived from sulphite soft woodpulp from which the fines have been removed and in amount of from O.S%%by Weight to the conditioned pulp and said fibers being predominantly inthe range of 1-19 mm. in length, dispersing the additives throughout themass by mixing whereby the Wood pulp fiber forms an intertangled fibermass to trap the grape solids and positioned to intercept and inhibitthe independent migration of finer particles, and maintaining themixture at a temperature with in the reaction range of the hydrollzingagent for a sufficient time to obtain a substantial hydrolizing effect,then progressively reducing the volume of the mass whereby the juice isextracted independently of the solids particles, the latter beingretained in their relatively dispersed positions in said mass.

23. A method for obtaining a high separation of liquids from solids in ahighly fluid vegetative pulp a predominant proportion of the liquidretaining particles of which are ruptured, comprising uniformlydistributing in such pulp from 0.55% by weight of cellulose fibersderived from sulphite soft wood pulp substantially free from fines andpredominantly in the range of l mm. in length, and then subjecting thepulp to compressive extraction to separate the liquid from a residualpulp comprising pulp solids retained by an intertangled mass of saidfibers.

24. A method for obtaining a hi h separation of liquids from solids in ahighly fluid vegetative pulp a predominant proportion of the liquidretaining particles of which are ruptured, comprising uniformlydistributing in such pulp alpha cellulose fibers substantially free fromfines and predominantly in the range of 11t) mm. in length, and inamounts elfective to condition the pulp by absorption of the liquid andto form a swollen intertangled mass, and then progressively reducing thevolume of the mass whereby the liquid is extracted independently of thesolids particles, the latter being retained in their relativelydispersed positions in said mass.

25. Process for conditioning vegetative material preparatory to theextraction of liquid therefrom, comprising adding to the mass ofvegetative material a pectic hydrolyzing enzyme composition and alphacellulose fibers substantially free from fines and predominantly in therange of l1() mm. in length, dispersing the additives throughout themass by mixing, maintaining the mixture at a temperature within thereaction range of the hydrolyzing agent for a surlicient time to obtaina substantial hydrolyziug meet, the added fibers being in amountseffective to condition the pulp by absorption of the liquid and to forma swollen intertangled mass, then progressively reducing the volume ofthe mass, whereby the liquid is extracted independently of solidparticles, the latter being retained in their relatively dispersedpositions in said mass.

26. The process of removing suspended solids from extracted liquid bythe addition of alpha cellulose fibers substantially free of fines andpredominantly in the range of 1ll) mm. in length, and in amountseffective to condition the liquid by absorption of the liquid and toform a swollen intertangled mass, and then progressively reducing thevolume of the mass whereby the liquid is extracted independently of thesolids particles, the latter being retained in their relativelydispersed positions in said mass.

27. A method for recovering high yields of low solids content pectinextract from citrus peel comprising comminuting the peel, combining thepeel with water, heating, draining off the water, providing a crumblymass, recombining with water, acidifying, reheating the resultingsuspension to form a gelatinous puree, uniformly distributing in suchpuree 0.55% by weight of alpha cellulose fibers substantially free fromfines and predominantly in the range of 1-10 mm. in length, and thenpassing the puree through a continuous extraction zone to separate thepectin extract from a residue consisting of citrus peel solids retainedby an intertangled mass of said fibers] 28. A method for recovering highyields of fiow solids content pectin extract from pectin bearingmaterials comprising, comminuting said materials, combining with water,heating and draining off water, providing a crumbly mass, recombiningwith water, acidifying, reheating the resulting suspension to form agelatinous puree, uniformly distributing in such puree O.5-5% by weightof alpha cellulose fibers substantially free from fines andpredominantly in the range of 1-10 mm. in length, and passing the pureethrough a continuous extraction zone to separate the pectin extract froma residue consisting of material solids retained by an intertangled massof said fibers.

29. A method for recovering high yields of low solids content pectinextract from pectin bearing materials comprising preparing thegelatinous puree of pectin and material solids, uniformly distributingin such puree 0.55% by weight of alpha cellulose fibers substantiallyfree from fines and predominantly in the range of l-lO mm. in length,and passing the puree through a continuous extraction zone to separatethe pectin extract from a residue consisting of material solids retainedby an intertangled mass of said fibers.

30. Process for conditioning grape material preparatory to theextraction of juice therefrom and extracting such juice, comprisingadding to a mass of grape material, a pectin hydrolizing agent in amountnot less than 9.2 nor more than 0.4% by weight of the initial pulp,incorporating with the mass of grape material and hydrolizing agent afinely divided wood pulp fiber prepared from commercially refinedbleached suifite soft wood pulp from which the fines have been removed,said fibers being used in amount of from O.S5% by weight andpredominantly in the range of 1-10 mm. in length, dispersing theadditives throughout the mass by mixing, whereby the wood pulp fiberforms an intertangled fiber mass to trap the grape solids and positionedto intercept and inhibit the independent migration of finer particles,and maintaining the mixture at a temperature within the reaction rangeof the hydrolizing agent for a sufiicient time to obtain a substantialhydrolizing effect, then progressively reducing the volume of the masswhereby the juice is extracted independently of the solids particles,the latter being retained in their relatively dispersed positions insaid mass.

31. Process for conditioning grape material preparatory to theextraction of juice therefrom and extracting such juice, comprisingadding to a mass of grape material, a pectin hydrolizing agent in amountnot less than 0.2 nor more than 0.4% by weight of the initial pulp,incorporating with the mass of grape material and hydrolizing agent afinely divided wood pulp fiber prepared from commercially refinedbleached sulfite soft wood pulp by screening the purified pulp to removethe fines, said fibers being used in amount of from 0.55% by weight andpredominantly in the range of 1-10 mm. in length, agitating the mixtureof said material and additives to secure uniform dispersion of theadditives throughout the mass whereby the particles holding materialforms an intertanglcd fiber mass to trap the fruit pulp solids andpositioned to intercept and inhibit the independent migration of finerparticles, holding the mass within a temperature range of fromsubstantially F. to F. for a duration of substantially from 10 minutesto 60' minutes, separating the optimum amount of substantiallysolids-free juice from the thus conditioned material, leaving a mass ofsolids with residual juice, and separating the extractable residualjuice from said mass by progressively reducing the volume of the masswhereby the juice is extracted independently of the solids particles,the latter being retained in their relatively dispersed positions insaid mass.

32. A method for obtaining high yields of low solids content juice fromgrapes comprising crushing and sternming the grapes to provide aninitial pulp, sieving said initial pulp to separate the same into apuree and a residual pulp, uniformly distributing in said puree 1-5% byweight of alpha cellulose fibers substantially'free from fines andpredominantly in the range of l-lO mm. in length, passing said pureecontinuously through a pressure extracting zone to recover free runjuice and provide a second quantity of in residual pulp containing saidfibers, using said residual pulp in combination with juice containingmaterial, and passing such combined material through a continuouspressure extraction zone to recover pressed juice.

33. A method for obtaining high yields of low solids content juice fromgrapes comprising crushing and sternming the grapes to provide aninitial pulp, sieving said initial pulp to separate the same into apuree'and a residual pulp, uniformly distributing in said puree l-5% byWeight of alpha cellulose fibers substantially free from lines andpredominantly in the range of l-lO mm. in length, passing said pureecontinuously through a pressure extracting zone to recover free runjuice and provide a second quan- "20 tity of residual pulp, containingsaid fibers, using said residual pulp in combination with juicecontaining mate- 'rial, and subjecting such combined material to aseparation'treatment to recover juice and a pomace containing alphacellulose fibers.

References Cited in the file of this patent UNITED STATES PATENTS2,128,432 Ramage Aug. 30, 1938 2,320,036 Harris May 25, 1943 2,507,827Staiford et a1 May 16, 1950 2,823,126 Little Feb. 11, 1958 2,837,431WOlcott June 3, 1958

1. A METHOD FOR OBTAINING A HIGH SEPARATION OF LIQUIDS FROM SOLIDS IN AHIGHLY FLUID VEGETATIVE PULP A PREDOMINANT PROPORTION OF THE LIQUIDRETAINING PARTICLES OF WHICH ARE RUPTURED, COMPRISING UNIFORMLYDISTRIBUTIONG IN SUCH PULP 0.5% BY WEIGHT OF ALPHA CELLULOSE FIBERSSUBSTANTIALLY FREE FROM FINES AND PREDOMINANTLY IN THE RANGE OF 1-10 MM.IN LENGTH, AND THEN SUBJECTING THE PULP TO COMPRESSIVE EXTRACTION TOSEPARATE THE LIQUID FROM A RESIDUAL PULP COMPRISING PULP SOLIDS RETAINEDBY AN INTERLTANGLED MASS OF SAID FIBERS.